Conveyors are mechanical devices that include a plurality of rollers (e.g., cylindrical or spherical rollers) for moving boxes, luggage, parcels and other items over the length of an upper conveying surface of the conveyor. The upper conveying surface can be horizontal, or at a fixed or adjustable incline (e.g., positive or negative slope relative to horizontal). Some conveyors have a series of telescopically connected sections that make the upper conveying surface extendible in length.
Some conveyors have powered rollers to propel the items across the upper surface. Some conveyors have passive free-spinning rollers that convey the items by gravity. In some cases, a moving belt overlays the rollers to support the conveyed items with a smoother, more evenly distributed surface. In some instances, the moving belt helps prevent conveyed items from getting caught in transitional areas between adjacent conveyor sections or between rollers within a section.